This report examines the significant decline in union density in New Zealand from 1991 to 2008, highlighting the impact of the Employment Contracts Act (ECA) of 1991 and the Employment Relations Act (ERA) of 2000. It explores how these legislative changes influenced union membership and collective bargaining. The report analyzes the stagnation of union density rates after the introduction of the ERA, despite its union-friendly intent, and discusses the factors that contributed to the decline in private sector union membership and collective bargaining, including employer attitudes and the changing nature of the labor market. The analysis covers the shift from industrial arrangements and collective bargaining to individualized employment relations, and the role of various factors such as legislative changes, employer resistance, and employee disinterest in the decline of collectivism. The report concludes that the decline in New Zealand union membership is ongoing, with workers increasingly relying on government and other bodies for benefits formerly provided by unions, leading to a potential decline in their relevance.